1. Field of the Invention
The present invention relates to an apparatus and method for detecting the position of an object. More particularly, the present invention relates to an apparatus and method for analyzing the position and path of an object through radio frequency identification (RFID) having a sensor.
2. Description of the Related Art
Conventional techniques of identifying the position of a moving object that has been proposed include a technique of tracking the position of the object by assigning an identifiable mark to the object and imaging and reading the moving object using a video camera, a technique of tracking the position of an object based on whether the moving object passes a specific position using an optical or physical sensor when the moving object reaches the specific position, a technique of tracking the movement of the object by attaching a radio frequency identification (RFID) tag to the moving object and disposing a plurality of RFID readers in several positions, etc.
The conventional video camera based method requires a complex process to analyze an image. The method requires expensive equipment performing a number of operations and also requires many pieces of equipment allowing object tracking in several positions since the method can be used to identify only the position in a limited area displayed on a screen.
Among the conventional position tracking techniques, the technique of identifying the position of the moving object based on whether the moving object passes a specific position can be used to identify the object moving from one position to a next position, but it is difficult to recognize intermediate movement of the object.
A position tracking system based on RFID has less restrictions on position track and places since RFID tags are disposed in a moving object and RFID readers disposed at several positions, but more expensive RFID readers are required compared to RFID tags.
U.S. Pat. No. 6,750,769 B1 in the name of Sun Microsystems Inc., entitled “Method and Apparatus for Using RFID Tags to Determine the Position of an Object,” describes a system of identifying the position and shape of an object disposed on a floor having an array of RFID tags in a limited area. The system determines the position and shape of the object by using the fact that an RFID reader cannot receive signals from RFID tags of the array in a region where the object is disposed on the floor.
In the foregoing patent, since identification of the position and shape of the object positioned on the array is based on information from RFID tags blocked by the object, when the RFID tags are disposed in a spare array, it is difficult to obtain the exact shape and position of the object since position information can be missed. Therefore, the RFID tags must form a dense array to identify the position and shape of the object.